Almost two decades after frontman Kurt Cobain’s death, the iconic grunge band Nirvana reformed with a new lead singer/guitarist: Sir Paul McCartney. The ex-Beatle joined the Foo Fighters singer and former Nirvana bassist as a part of the 12.12.12 concert, a benefit show for victims of Hurricane Sandy, reports the Sun.

“I didn’t really know who they were," the Beatle said of being in the studio with Grohl and Novoselic, according to the Guardian. "They are saying how good it is to be back together. I said ‘Whoa? You guys haven’t played together for all that time? And somebody whispered to me ‘That’s Nirvana. You’re Kurt.’ I couldn’t believe it.”

Cobain committed suicide in April of 1994, at the height of Nirvana’s popularity.